Automatic punch press



' Feb. 3, 1959 E. w. GIETL 2,871,811

AUTOMATIC PUNCH PRESS Filed Jan. 7, 1955 S Sheets-Sheet 1 Edward W GLefl Feb. 3, 1959 E. w. GIETL AUTOMATIC PUNCH PRESS s Sheets-Sheet 2 Filed Jan. 7, 1955 Feb. 3, 1959 w, 2,871,811

AUTOMATIC PUNCH PRESS Filed Jan. '7, 1955 3 Sheets-Sheet 3 722 2 IZZQT Edward W. 62222! of the press when the article would nited States Patent 2,87 1,8 l i Patented Feb. 3, 1959 AUTOMATIC PUNCH PRESS Edward W. Gietl, Highland Park, 111., assignor to Hondaille industries, Inc, a corporation of Michigan Application January '7, 1955, Serial N 0. 480,397 2 Claims. (Cl. 113-50) This invention relates to an automatic punch press and more particularly an automatic punch press provided with means for preventing maloperation thereof and damage thereto.

This invention is applied to an automatic punch press which incorporates means, such as an automatically operated' air blast, for ejecting a formed article therefrom. According to this invention, means are provided for sensing the ejection of a formed article from the press, and means actuated by such sensing means are effective for initiating operation of the press.

With this arrangement, if a part should become jammed in the press, operation of the press is stopped because ejection of an article from the press is required to initiate further operation thereof. Thus, damage to the press is obviated.

The operation of the press may preferably be com pletely automatic with means being provided for feeding the required amount of material to the press. In one preferred arrangement, such feeding means is actuated from the means sensing the ejection of a formed article from the press, and means responsive to the feed of the required amount of material to the press are effective for initiating operation of the press.

In another preferred arrangement, the press is controlled directly from the sensing means and the feeding means are controlled from the press. This has advantages over the first-described arrangement in that it is possible to cause operation of the feeding means during the last portion of the cycle of operation of the press (the upstroke in an ordinary press) and a much higher speed of operation is possible. However, the first-described arrangement may have advantages in certain applications in that operation of the press is not initiated until after the feed of the material thereto.

In one preferred form, the sensing means comprises a movable gate, preferably pivoted, in the path of ar ticles ejected from thepress which is used to actuate suitable control means such as an electric switch. In another preferred form, the sensing means comprises a coil so situated relative to the path of articles ejected from the press that the articles pass through the field of the coil. The ejection of the article is detected by sensing the change in impedance of the coil caused by the presence of the article in its field. This form of sensing means has advantages over the first-described form in that no actual contact With-the article is required. The first-described form, however, has advantages in that no complex apparatus is required, as is required by the second-described form. It will be appreciated, of course, that other forms of sensing means could be used within the broad concepts of the invention.

Another feature of the invention is in the provision of means for preventing the sensing means from being effective except in the portion of the cycle of operation normally be ejected therefrom.

An object of this invention, accordingly, is to provide an improved automatic punch press or the like with means for preventing maloperation thereof and damage thereto.

This invention contemplates other and more specific objects, features and advantages which will become more fully apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate preferred embodiments and in which:

Figure 1 is a side elevational view of an automatic punch press system constructed in accordance with the principles of this invention;

Figure 2 is an electrical circuit diagram of electrical apparatus used in the system of Figure l;

v Figure 3 is aside elevational View of another preferred form of an automatic punch press system constructed in accordance with the principles of this inven- I tion;

Figure 4 is a detail view of a sensing coil used in the arrangement of Figure 3, looking substantially along line lV-IV of Figure 3;

Figure 5 is an electrical circuit diagram of a portion of the electrical control apparatus used in the arrangethe die, and a movable die or hereinafter referred to as the punch.

I to complete one cycle of operation.

'ment-or" Figure 3; and 25 Figure 6 is. an electrical circuit diagram of another portion of the electrical control apparatus used with the system of Figure 3.

suitable conventional apparatus is employed which may include an electric drive motor 13, means for converting A rotary to reciprocating motion, and clutch means between ingthe formed article from the press.

such means and the electric motor 13.

' Suitable'means, not shown, are provided for knocking the formed article out of the punch 12 on the upstroke thereof, and means are provided for then eject- For this pur- 14 is provided which is coupled through a line 15 and a valve 16 to a source of compressed air, notshown. The air valve'i6 is automatically opened on the upstroke of the press by means of a cam actupose, an air jet 'ator 17 carried by the punch 12. When the formed article is ejected from the press 10 by an air blast from the nozzle 14, it may fiy over onto a conveyor generally designated by a reference numeral 18 which transports the formed article to a desired location.

The material from which an article is formed by the press-10 may be continuous sheet stock supplied from an automatic centering reel assembly 19 and intermittently fed to. the press 10 by an automatic feeding and straightare all known in the "scribed in detail herein.

110. in one preferred form,

ening machine 20. The press 10, the conveyor 18, the reel 19 and the feeding and straightening machine 20 prior art, and are therefore not de- -According to this invention means are provided for sensing the ejection of a formed article from the press such sensing means corn prises a movable gate 21 in the path of travel of ejected articles from the press 10 to the conveyor 18. The gate 21 preferably comprises a plurality of horizontally spaced parallel bars and is preferably pivotally supported from a bracket 22 secured to the frame of the press 10 for movementabout a horizontal axis 23.

The gate zl, when struck by an article ejected from the press will be pivoted in a clockwise direction, as viewed in Figure 1, and an actuator 24 carried by the gate 21 engages the operating button of a micro-switch 25 carried by the bracket 22. The micro-switch 25 is connected through a cord or cable 26 to a control box 27 mounted on the frame of the press 10. The control box 27 is connected through a cord 28 through a source of electrical power, such a source of 60 cycle 110 volt alternating current, and is also connected through a cable or cord 29 to a control unit 30 mounted on the feeding and straightening machine 20. The control unit 30 is connected to a source of electrical power through a line cord 31 and is also connected through a cord 32 to a control for the press 10, not shown.

In operation, a start button 33 on the control unit 30 may be depressed to initiate operation of the feeding and straightening machine 20. The machine 20 will feed the required amount of sheet material to the press 10 after which a signal is transmitted through the cord 32 to initiate operation of the press 10. The punch 12 will then be moved downwardly against the die 11 to form an article and on the upstroke of the punch 12, the article will be ejected by suitable means therefrom and thereafter the air valve 16 will be opened by the cam actuator 17 and a blast of air from the nozzle 14 will be directed against the article to blow it toward the conveyor 18. The article in passing from the press 10 to the conveyor 18 engages the gate 21 and swings it in a clockwise di rection to engage the actuator 24 with the button of the micro-switch 25. The micro-switch 25, through the control units 27 and 30 will initiate operation of the feeding and straightening machine 20 to repeat the cycle. This cycle will, of course be repeated over and over again until stopped intentionally by actuation of a suitable switch on the control unit 30 (or on the control unit 27) or until a formed article is not ejected from the press 10 either from jamming in the dies or from lack of feed of material thereto.

It can happen that the circuit which initiates operation of the feeding and straightening machine 20 may become accidentally energized during the cycle of operation of the press 10 so that the machine 20 might attempt to feed an additional amount of material to the press 10. For example, after the gate 21 is swung in a clockwise direc tion by an ejected article, it will swing back in a counterclockwise direction and then through pendulum action may swing again in a clockwise direction to actuate the micro-switch 25. Also, due to jarring forces from the' operation of the press 10, relays or the like and the control units 27 or 30 might become accidentally energized. According to a specific feature of the invention, means are provided for preventing such occurrences from having any effect on the operation of the system. For this purpose, the control unit 27 is connected through a cord 34 to a micro-switch 35 carried by the frame of the press 10 and having an actuator in the path of a cam 36 carried by the punch 12. During portions of the cycle of operation of the press 10 other than that portion when a formed article would normally be ejected therefrom, the cam 36 actuates the micro-switch 35 and the circuit is so arranged that the circuit for initiating operation of the feeding and straightening machine 20 is then rendered ineffective.

One form of circuit arrangement that may be used with the system of Figure 1 is illustrated in Figure 2. Referring thereto, the micro-switch 25 is connected through conductors of the cord 26 to terminals 37 and 38 on the control unit 27. The terminal 37 is connected to one side of a low voltage secondary winding 39 of a transformer 40 and the terminal 38 is connected through a relay coil 41 to the other side of the low voltage secondary winding 39. The transformer 40 has a primary winding 42 one end of which is connected through an on-off switch 43 to a terminal 44 with the other end of the primary 42 being connected directly to a terminal 45. The terminals 44 and 45 are connected to conductors of the line cord 28 which, as previously indicated may be connected to a source of 60 cycle 100 volt alternating current.

When the on-ott' switch 43 is closed and when the microswitch 25 is closed by the gate 21, the coil 41 will be energized and it will function to engage a movable contact 46 with a fixed contact 47. The movable contact 46 is connected to a terminal 48 connected to one conductor of the cord 29, the other conductor of the cord 29 being connected to a terminal 49. The fixed contact 47 is connected to a terminal 50 connected to one conductor of the cord 34, which is connected to the switch 35, the other conductor of the cord 34 being connected to a terminal 51 which is connected directly to the terminal 49. The operation of the switch 35 is such that it is open when the actuator thereof in engaged by the cam 36, but it is otherwise closed. Accordingly, if the press 10 is in the portion of the cycle of operation when a formed article would normally be ejected therefrom, engagement of the contacts 46, 47 through energization of the coil 41 by closing of the micro-switch 25 will complete a circuit between the terminals 48 and 49 connected to the cord 29.

The conductors of the cord 29 are connected, at the control unit 30, to a pair of terminals 52, 53. The terminal 53 is connected to one side of a low voltage secondary winding 54 of a transformer 55 and the terminal 52 is connected through a relay coil 56 to the other side of such secondary winding 54. The transformer 55 has a primary winding 57 connected to conductors 58 and 59 which are connected through a switch 60 to terminals 61 and 62 connected to conductors of the line cord 31 which maybe connected to a source of 60 cycle 110 volt alternating current. The conductors 58 and 59 may also be connected to terminals 63 and 64 which may be connected to a drive motor and other apparatus of the feed ing and straightening machine 20.

With the switch 60 closed and when the circuit between terminals 52 and 53 is completed from operation of the sensing switch 25, the relay coil 56 will be energized and will engage a movable contact 65, connected to a terminal 66 with a fixed contact 67 connected to a terminal 68, so that a circuit is completed between terminals 66 and 68 when a circuit is completed between terminals 52 and 53. Through a suitable control arrangement (not shown), completion of the circuit between terminals 66 and 68 functions to initiate operation of the feeding and straightening machine 20. Upon completion of the feed of the required amount of material, a circuit will be completed between a pair of terminals 69 and 70 on the control unit 30, the terminal 69 being connected through a relay coil 71 to one side of the low voltage secondary winding 54 and the terminal 70 being connected directly to the other side of the low voltage secondary winding 54. Thus, upon completion of the feed of the required amount of material, the relay coil 71 will be energized and it will engage a movable contact 72 connected to a terminal 73 with a fixed contact 74 connected to a terminal 75. The terminals 73 and 75 are connected to conductors of the cord 32 and completion of the circuit therebetween will initiate operation of the press 10 through a suitable control arrangement, not shown. In such an arrangement, for example, an electrical device for tripping a one-revolution clutch may be energized to cause the press 10 to go through one cycle of operation.

It may be noted that the start button 33 may complete the circuit between the terminals 66 and 68 to thus initiate operation of the feeding and straightening machine 20.

Referring now to Figure 3, another preferred form of automatic punch press system is illustrated. This system comprises a punch press 76 substantially identical to the punch press 10 and including a die-carrying bolster plate 77, hereinafter referred to simply as the die, and a movable die or punch-carrying slide 78, hereinafter referred to simply as the punch. The punch 78 is moved downwardly and upwardly. by means including an electric motor 79. A nozzle 80, like the nozzle '14 of the press 10, is connected through a conduit 81 and through an air valve 82 to a'source of compressed air, not shown, the air valve 82 being actuated on the upstroke of the punch 78 by a cam actuator 83. Articles ejected from the press 76 fly over onto a conveyor 84, identical to the conveyor 18, andstock is fed to the press 76 from a supply reel 85, identical to the reel 19, by an automatic feeding and straightening machine 86, identical to the machine 20. i

The system of Figure 3 utilizes a modified form of sensing meansforsensing the ejection; of a formed article fron the press 76. Such se nsing. means comprises a coil 87 supported from the frame of the press 76 by a pair of brackets 88 and a pair of brackets 89 in a position such that an article ejected from the press 76 will pass through the coil 87. The coil 87 may preferably have a generally rectangular shape as illustrated in Figure 4.

The coil 87 is connected through a suitable cord or cable 90 to a control unit 91 mounted on the frame of the press 76, the unit 91 being connectable to a suitable source of power through the line cord 92. The control unit 91 could be used to initiate operation of the feeding and straightening machine 86 with the operation of the press 76 being controlled from the machine 86, as in the arrangement of Figures 1 and 2. Preferably, however, the control unit 91 may be coupled through a suitable cord 93 to a suitable control arrangement, not shown, which initiates operation of the press 76 and the operation of the feeding and straightening machine 86 may be controlled from the press 76.

conductor of the line cord 92.

In particular, a micro-switch 94 is supported from the frame of the press 76 with its actuator in the path of a cam member 95 carried by the punch 78. On the upstroke of the punch 78, at or about the same time as the valve 82 is opened, the switch 94 will be actuated and it controls initiation of the operation of the feeding and straightening machine 86.

For this purpose,. the micro-switch 94 is connected through a suitable cord 96 to a control unit 97 which is connected through a cord 98 to a suitable source of power and is also connected through a cord 99 to a control unit 100 on the feeding and straightening machine 86.

In the vent it is desired to manually initiate operation of the feeding and straightening machine 86, a start button 101 may be depressed. Similar means, not shown, may be provided for initiating operation of the press 76 manually.

The control unit 91 may have a circuit such as is illustrated in Figure 5 with the sensing coil 87 being connected through conductors of the cable 88 to terminals 102 and 103 of the control unit 91, the terminal 102 being connected to the terminal 103 through a variable capacitor 104 which defines with a coil 87 a resonant circuit. This resonant circuit may form part of an oscillator circuit with the vterminal 103 being connected through a grid-leak capacitor 105 and grid-leak resistor 106, in parallel, to a control grid 107 of a triode 108 having a cathode 109 and a plate 110. The terminal 102 may be connected directly to a ground connection. A tuned grid-tuned plate type of oscillator may be used with the plate 110 connected through a coil 111 and a variable capacitor 112 in parallel to a terminal 113 of a power supply unit 114, terminal 113 may be at a high positive potential relative to another terminal 115 connected to ground. The power supply 114 has input terminals 116 and 117, the terminal 116 being connected to a terminal 118 connected to one conductor of the line cord 92 and the terminal 117 being connected through an on-ofi The cathode 109 of the triode 108 may be connected through a resistor 121 to ground and also to an input terminal 122 of an amplifier 123having another input terminal 124 connected to ground. The amplifier 123 may have a power input terminal 125 connected to a terminal 126 of the power supply 114 and has output terminals 127 and 128 connected to a relay coil 129 which is arranged to actuate a movable contact 130 into engagement with a fixed contact 131, when actuated, the contacts 138 and 131 being connected to terminals 132 and 133 connected toconductors of the cord 93.

1h operation, the variable capacitors104 and 112 may be adpusted to obtain oscillation of the oscillator circuit and may preferably be adjusted so that the current through the triode .108 is at a minimum, as will be achieved when the resonant grid and plate circuits are tuned to substantially the same frequency which will be well understood by those skilled in the art.

When a formed article is ejected from the press 96, it will pass through the coil 87 and the resonant frequency of the circuit including the coil 87 and the capacitor 104 will be changed due to the effect of the article on the field of the coil 87. This change in the resonant frequency will cause an increase in current through the triode 108 with a corresponding increase in the voltage across the resistor 121. Thus, a voltage pulse will be applied to the input terminals 122 and 124 of the ampliher 123 when the formed article passes through the coil 87. This voltage pulse is amplified and causes energization of the relay coil 129 to an extent sufiicient to engage the contact 130 with the contact 131 and complete a circuit between the terminals 132 and 133. Through the cord 93, and the control arrangement of the press 76, this will initiate operation of the press 76.

Referring now to Figure 6, the circuits for the control units 97 and 100 are illustrated. In particular, the micro-switch 94 is connected through conductors in the cord 96 to terminals 134 and 135 of the control unit 97. The terminal 135 is connected through a relay coil 136 to a low voltage secondary winding 137 of a transformer 138, the terminal 135 being connected to the other side of Such low voltage secondary winding 137. The transformer 138 has a primary winding 139, one end of which is connected to a terminal 140, the other end thereof being connected through a switch 141 to a terminal 142. The terminals and 142 are connected to conductors of the line cord 98 which may be connected to a suitable source of power, such as a source of 60 cycle, 110 volt alternating current.

The coil.136 is energized when the switch 94 is closed and is arranged to engage a moveable contact 143 with a fixed contact 144, the contacts 143, 144 being connected to terminals 145 and 146, which are connected through conductors of the cord 99 to terminals 147 and 148 on the control unit 100. Another pair of terminals 149 and 150 on the control unit 97 are connected to the power line terminals 140 and 142 and are also connected through conductors of the cord 99 to terminals 151 and 152 on the control unit 100.

The terminals 147 and 148 of the control unit 106 are connected directly to terminals 153 and 154 which are connected to a suitable control circuit, not shown, which initiates feed of stock by the feeding and straightening machine 86 when a circuit is completed between the terminals 153 and 154. The start button 101 may thus be arranged to complete a circuit between the terminals 153 and 154.

The terminals 151 and 152 of the control unit 100 are connected to terminals 155 and 156 through a switch 157, the terminals 155 and 156 being connected to an electric drive motor and other electrical apparatus of the feeding and straightening machine 86.

It will, accordingly, be appreciated that this invention tions and variations may be efiected without departing from the spirit and scope of the novel concepts of this invention.

I claim as my invention:

1. In a punch press or the like including means for ejecting a formed article therefrom, means for sensing the ejection of an article from vthe press, means actuated by said sensing means for initiating operation of the press, and means for preventing said sensing means from u being effective except in the portion of the cycle of operation of said press When the article would normally be ejected therefrom.

2. In a punch press or the like including means for ejecting a formed article therefrom, a switch arranged to be closed for initiating a cycle of operation of said press, means responsive to ejection of an article from said press for closing said switch, and a second switch in series with said first switch and arranged to be closed only in the portion of said cycle of operation when an article is normally ejected from said press.

Shaw Dec. 21, 1943 Lyon Jan. 12, 1954 

